public async Task <IWordTree> BuildFrom(Stream stream)
{
Debug.Assert(stream != null);
using var reader = new StreamReader(stream);
IWordTree tree = new WordTree();
string currentLine;
while ((currentLine = await reader.ReadLineAsync()) != null)
{
tree.AddWord(currentLine);
}
return(tree);
}
protected List <char[]> FindWordsIn(char[] prefix, char[] remaining)
{
Debug.Assert(prefix != null);
Debug.Assert(remaining != null);
if (remaining.Length <= 0)
{
return(new List <char[]>());
}
// foreach letter in remainig
// combine with prefix and then call again
List <char[]> found = new List <char[]>();
for (int index = 0; index < remaining.Length; index++)
{
char ch = remaining[index];
char[] newprefix = new char[prefix.Length + 1];
Array.Copy(prefix, newprefix, prefix.Length);
newprefix[newprefix.Length - 1] = ch;
Console.WriteLine(newprefix);
// TODO: Update wortree to use char[]
var newprefixstr = new string(newprefix);
if (newprefixstr.Length >= MinWordLength &&
WordTree.IsWord(newprefixstr))
{
found.Add(newprefix);
}
char[] newremaining = new char[remaining.Length - 1];
int newremindex = 0;
for (int i = 0; i < remaining.Length; i++)
{
if (i == index)
{
// skip this one
continue;
}
newremaining[newremindex] = remaining[i];
newremindex++;
}
found.AddRange(FindWordsIn(newprefix, newremaining));
}
//foreach(char ch in remaining) {
// char[] newprefix = new char[prefix.Length + 1];
// Array.Copy(prefix, newprefix, prefix.Length);
// newprefix[newprefix.Length - 1] = ch;
// Console.WriteLine(newprefix);
// // TODO: Update wortree to use char[]
// if (WordTree.IsWord(new string(newprefix))) {
// found.Add(newprefix);
// }
// char[] newremaining = new char[remaining.Length - 1];
// newremaining = remaining[1..];
// found.AddRange(FindWordsIn(newprefix, newremaining));
//}
return(found);
}
